Jinchūriki
The jinchūriki (人柱力; Literally meaning "Power of Human Sacrifice") are humans that have Tailed beasts sealed within them. They exhibit extraordinary powers, and in some cases are more powerful than their tailed beasts, because they have the intelligence to use the beasts' powers effectively. History The first jinchūriki was the Sage of the Six Paths, who sealed the Ten-Tailed Beast within himself to save the world. However, knowing that his death would release the Ten-Tails back into the world, the Sage used Izanagi to divide its chakra into the nine tailed beasts, before using Chibaku Tensei to seal its body away in what would become the moon. By the time of the formation of the shinobi villages, Hashirama Senju, the First Hokage, used his Wood Release techniques to capture and give several tailed beasts to the other shinobi villages as peace treaties, in order to stabilize the balance of power between them, but after Hashirama's death, the villages had trouble containing the beasts. The Second Kazekage of Sunagakure was the first to research the jinchūriki, with the other villages following soon after, with hopes to use the beasts as weapons in human hosts, or in Konohagakure's case, keep the beasts from doing harm to their village. In order to prevent the jinchūriki from turning traitor, it is tradition for the host to be selected from the family of the village's own Kage. In this way, the jinchūriki not only has strong ties of loyalty to village and their leader, but they also serve to show off the Kage's might. For example, Gaara is the son of the Fourth Kazekage, and Killer Bee is the son of the Third Raikage. Sealing Each village has used a different seal when creating their jinchūriki. For example, Konoha used the Eight Trigrams Sealing Style, and Kumogakure used the Iron Armor Seal. Akatsuki, an organization whose role in the series was to capture the jinchūriki, used the Illusionary Dragon Nine Consuming Seals to extract and seal the tailed beasts within the Demonic Statue of the Outer Path for future use. They have, as of the Fourth Great Shinobi World War, captured seven of the nine beasts. If the tailed beast is removed from its jinchūriki's body, the jinchūriki will die. Similarly, if the jinchūriki dies with the tailed beast still sealed within them, the beast will die too. Because of this, the tailed beasts tend to be very protective of their jinchūriki, and will take any action whenever their lives are in danger. However, this was not always the case; before the Nine-Tailed Fox was sealed into Naruto, it was said that it could survive its jinchūriki's death, with the only consequence being that it would take time for it to be revived. Also, rare exceptions of a jinchūriki surviving an extraction may occur, if the said host has high enough stamina. The seal that keeps a tailed beast within its female jinchūriki is at its weakest when she is in childbirth, due to the nurturing of the child in the womb using the power of the seal, weakening the seal in direct proportion. As such, a ninja is required to keep the seal intact during childbirth, and restore the seal back to full power afterwards. A full-term pregnancy for a female jinchūriki is about ten months, presumably because the body has to nurture both the child and the seal simultaneously, as a result the child develops more slowly. Personality The jinchūriki are typically lonely people, viewed by those around them as the tailed beast that has been sealed within them, leading to prejudice and being hated and feared. According to Akatsuki, the first two jinchūriki they captured loathed humanity, and their villages were in fact glad to be rid of them. However, some jinchūriki refuse to waver, even though they have been shunned. They seem to have a cheerful demeanor. Two examples are Killer Bee and Naruto. Control The jinchūriki have the potential to control their tailed beasts through sheer willpower and concentration, but requires a lot of training in order to retain it. If an inexperienced jinchūriki transforms deeper into their tailed beast's forms, their personality tends to corrode into animal instincts, becoming not only more ferocious in battle, but also increasingly dangerous to their friends and allies. The best training spot for a jinchūriki to control their tailed beast is at the Falls of Truth. According to Gerotora, it is implied that the tailed beast's power consists of two parts: its chakra and its will. For example, whenever Naruto drew out the Nine-Tails' chakra, its will containing its hatred would fuse along with it, relentlessly trying to control Naruto whenever given the chance. To control its power, Naruto must have his own will and heart both very strong and free of hatred, in order to separate the Nine-Tails' will from its chakra completely. Gaara's control over Shukaku had increased in the beginning of Part II, where he could create and use its giant arms multiple times. Yugito also had shown a high level of control, being able to fully transform into the Two-Tailed Cat with ease. In the anime, Utakata could assume the form of the Six-Tails as well. However, their control was lacking compared to Yagura and Killer Bee's, as they became the jinchūriki to have complete control of their tailed beasts' power. While Naruto now has full access to the Nine-Tails' chakra, he has only recently gained control over it. According to the Eight-Tailed Ox, once the jinchūriki is able to completely wield their tailed beast's chakra, both the tailed beast and its jinchūriki must share no hostility towards each other. They also have to have agreements of trading certain amounts of their own chakra, which can allow the jinchūriki to willingly transform into their tailed beast and be able to perform the Tailed Beast Ball without losing any control. Otherwise, the transformation without the tailed beast's cooperation will result in failure, and the tailed beast will then gradually consume its jinchūriki's own chakra whenever they use its chakra, which can kill the jinchūriki. In Naruto's case, the Nine-Tails isn't the type to cooperate with its jinchūriki to do anything. Abilities The jinchūriki have shown to have access to great amounts of chakra and access to unique fighting styles and abilities, depending on their tailed beast: Gaara manipulates sand, Yugito breathes fire, Rōshi created lava, Killer Bee spat ink, and Naruto had quick regeneration and is able to sense negative emotions (after controlling the Nine-Tails' chakra). By training, they can gain additional access to their tailed beast and its chakra, such as Killer Bee being able to synchronize with the Eight-Tails, and transform himself into it; and Naruto accessing the Nine-Tails' Yang chakra only when he needs it, and giving him a chakra shroud that resembles the Sage of the Six Paths. Tailed beasts can also provide their jinchūriki with constant advantages, such as Gaara's self-activating Shield of Sand which automatically protects him, even from self-injury; and Naruto's healing factor that immediately activates as soon as he incurs wounds.